J. Phys. IV France 112 (2003) 1009
Time-dependent dynamic response of martensite in Ni-Mn-Ga magnetic shape memory alloys to stress caused by constant magnetic fieldN. Glavatska1, I. Glavatsky1, Y. Ge2 and V.K. Lindroos2
1 Institute for Metal Physics, Vemadsky Blvd. 36, 03680 Kiev 142, Ukraine
2 Helsinki University of Technology, Laboratory of Physical Metallurgy and Materials Science, P.O. Box 6200, 02015 Hut, Finland
This work presents the original experimental results concerning study of new phenomenon - time-dependent behaviour under a constant magnetic field and some effects recently found concerning the kinetics of stress relaxation in Ni-Mn-Ga alloys. Three non-stoichiometric Ni-Mn-Ga alloys, producing large magnetic shape memory effect (MSME) up to 5% at room temperature, were investigated. It was found from the time dependence of the magnetic field induced strain at constant magnetic field and set temperature that the material gradually deforms under constant magnetic field in a manner analogous to mechanical creep under constant applied compressive stress.
© EDP Sciences 2003